package com.sls.core.util;

import java.security.MessageDigest;

import org.apache.log4j.Logger;

public class SHA1Util {

	private static Logger log = Logger.getLogger(SHA1Util.class);
	private static final char[] HEX_DIGITS = { '0', '1', '2', '3', '4', '5',
			'6', '7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f' };

	/**
	 * 加密字符串
	 * 
	 * @param src
	 * @return String
	 */
	public static String encrypt(String src) {
		if (src == null) {
			return null;
		}
		try {
			MessageDigest messageDigest = MessageDigest.getInstance("SHA-1");
			messageDigest.update(src.getBytes());
			return getFormattedText(messageDigest.digest());
		} catch (Exception e) {
			log.error("加密出现异常", e);
		}
		return null;
	}

	/**
	 * 把字节数组转成字符串形式
	 * 
	 * @param bytes
	 *            the raw bytes from the digest.
	 * @return the formatted bytes.
	 */
	private static String getFormattedText(byte[] bytes) {
		int len = bytes.length;
		StringBuilder buf = new StringBuilder(len * 2);
		// 把密文转换成十六进制的字符串形式
		for (int j = 0; j < len; j++) {
			buf.append(HEX_DIGITS[(bytes[j] >> 4) & 0x0f]);
			buf.append(HEX_DIGITS[bytes[j] & 0x0f]);
		}
		return buf.toString();
	}

	public static void main(String[] args) {
		System.out.println("111111 SHA1 :" + SHA1Util.encrypt("1"));
	}

}
